Indicating electric fuse-plug.



J. H. MILLER.

INDIGATING BLEUTRIUFUSE PLUG.

APPLICATION FILED APRA, 1912.

191 (31,946, Patented June 30,1914

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4UNrrEDv STATES' PATENT OFFICE.

- HN H. MILLER, F BRIDGEPOBT, CONNECTICUL-ASSIGNOR OF ONE-HALF TO JOHN L.

CARPENTER, OF BRIDGEPORT, CONNECTICUT. I

" To all whom it may concern Specification of Letters Patent.

Patented June 30', 1914.

applicati@ mea-A111114, 1912. smal-No. 688,549.

'Be it known that I, JOHN H. Minima-citi- .zen of the United States, and resident of Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Indicating Electric Fuse-Plugs, of which the following is a specification.

This invention relates to inclosed electric fuses of the plug type, such as are used in electric llighting circuits.

It is the object of the invention to provide means for indicating the condition of the fuse plug at all times so as to ascertain readily whether ,or no-t the same has been blown, said means being so located as to be visible without the necessity of removing the fuse from its socket or of disconnecting any part of the plug; and particularly to provide an external disk or label for the plug, which is `so arranged as to be punctured and destroyed by the blowing of the fuse, and to be projected outward in a way to form an extended portion that, may be readily detected by day or night.

To the above end the indicating means is designed to be operated by the burning of the fuse and the expanding. gases produced by the burning of the fuse, and is so arranged as to indicate upon the surface of the plug'when the fuse is blown. This' indicating means is outside where it can readily be seen by day, and examined by night, without the aid of a light, by simply feeling over the end of the plug, to determine whether or not the label is broken and the movable indicating member is projected outward from the body of the Vith these and other objects in view the invention consists in the construction and novel combination and arrangement of parts hereinafter fully described, illustrated in the accompanying drawings, andpointed out in the claims hereto appended, it being understood that various changes in the form, proportion, size and minor details of construction within the scope of the claims may be resorted to without rdeparture from the spirit or sacrificing any of the advantages of the invention.

Similar characters of reference denote like or corresponding parts throughout. the sev.

eral figures of the accompanying drawings,

is provided 16 to engage forming a part of this specification, and upon which- Figure 1 shows a central vertical longitudinal section through my improved electric fuse plugcomplete; Fig. 2 is an inner end.

'view of' e main body member of the plug; Fig. 3 1s a similar inner end view of the `flanged end member for inclosing the said body, Fig. 4 shows a disconnected perspectlve view of the fuse, screw, washer and terminal plate, shown assembled in Fig. 1;

Fig. 5 is a detached perspective view of the movable member, that is operated by the burning of the fuse; Fig. 6 is a longitudinal section of the sheet metal screw'shell; Fig. 7 shows a detached perspective view of the spring shown in Fig. 1 for actuating the indicating pin.

Referring in detail to the characters of reference marked upon the drawings, 1() indicates the main member or body of the plug which is preferably formed of porcelain, and as will be seen has an opening therethrough, the inner portion 12 of said opening being larger' than the outer end 11, to form an inclosed chamber. The outer end of the body member is enlarged as shown, while the reduced peripheral portion is threaded to re- 'ceive a correspondingly threaded shell 13 that serves to hold thc several part-s of the lug in place when assembled. The threads of this shell also serve to allow the plug to be vscrewed into a' base orl socket (not shown). An end member 14: which is also formed of porcelain is fitted into the open end of the large chamber 12 and is provided with an annular fiange 15 that fits against the annular end of the body member. 'A lug 15a lupon the outer face of this end member 15 engages a pocket 10u in the inner edge of the vmain member 10 to prevent the parts from turning with respect to each other when the shell is attached. The outer end of the shell with an inwardly turned flange the outer side of the flange 15 in`a manner to securely hold the same and end member up in place within the body member, when the shell is screwed on to the peripheral threads of thev body member. This shell is originally formed in the shape shown in Fig. G, with its inner edge 17 disposed forward, andlis thus run onto the plug, and flanged end member, to secure the two tol gether, after which the said inner edge porthe burnin bore of the end member 14.

tion 17 of the shell is spun down against the side of the last thread, as shown in Fig. 1, to prevent the shell from being turned off.

As shown in Fig. 1, I employ a movable indicating pin 18, having a point-ed end 19, which is normally located in the reduced end 11 of the body'member, and a head 20, fitted to operate like a piston in the larger borev of the body. A liber Washer 20l is fitted 'upon the pin and against the head so as to form a close it within the chamber 12. The top side of this piston or head is normally seated against the end of the above mentioned end member 14, and is free to be forced out by a spring 33 when released by of the fuse Within the end member, and t ereby cause the pointed end of lthe pin to puncture the paper seal, or label 21 shown in this ligure as being pasted on the end of the body and over the hole 4in which the said pin operates, thus leaving the seal broken and the pointed end of the pin projecting well through the hole in the end of the body member.

The spring 33 shown in Figs. 1 and 7 is bent into loo form and its end portion 34 is thus held y a small Washer 35 made of suitable soft metal that is designed to be melted at the proper time by the heat from the fuse. This spring is transversely seated in suitable notches 36-36 in inner end of part 14, and so that the spring will be situated opposite the center of the head of the pin. It willA also be noted that the end portion 34 of the spring which is to be released,

head of the pin so that when released by the melting of the washer, itavill strike the head and drive the pin forward and out through the cap 21.

The'fuse is preferably formed of round Wire having the two end portions 23 and 24 flattened u more or less as shown in Fi 4. The outer end 23 of this fuse is secure between the flange 16 of the above mentioned shell and the notch periphery of end member 111, to form `both an electrical and mechanical connection with the said shell. The body of the fuse is extended back through the longitudinal groove 25, inside of the body 10 of the plug and is then passed in through a notch 2G in end of member The intermediate portion 22 is bent over the spring 33 and extended into the The iattened end 24 of the fuse is bent around and eX- tended through the slot 27 of washer 28, contained within the inner end of the end member. This washer is engaged by a screw 2) or rivet that passes through a central hole of the head of the end member, and engages a plate 30 arranged on the outer end of the head of the end member to form the central contacting point or terminal for the fuse. This plate 30 is provided with two inturned-points 31 t-hatvengage small holes in the head of the end member to prevent the plate from turning when assembled. The intermediate portion 22 of the fuse, that passes over the spring is designed to be the Weakest point in the fuse, and, consequently, is where it burns across, causing an expansion of gases that forces the pin out through the paper cap. This part of the fuse is obviously situated within the end member, and is thus completely inclosed. The force of the combustion Within the chamber in this instance, has its effect upon the piston, forming one end Wall of said chamber, and drives it andthe pin out, the

latter being forced through the seal, while the piston stops against the inner end Wall of the body. It will thus be seen that the indicating pin 18 may either be actuated by the spring When released, as explained, or by the expansion of the gases causedby the burning of the fuse, or by both said spring and gases, according to the articular reason which caused t-he fuse to urn across or heat as the case may be. The burning of the fuse is usually caused b heavy overload or short circuit and is quie r, causing a sudden puff o1' expansion of the gases sufficient to cause the pin to shoot out, and in which case the spring may not be released. On the other hand, if the fuse becomes gradually overheated. due to different conditions, it in turn vwill heat the Washer 35 in a Way to melt the same and release the spring as i heretofore described. is that which is located adjacent to the From the foregoing it will be seen that I have produced a simple and desirable form 'of construction, which can be inexpensively manufactured. The fuse which ordinarily has to be soldered to one or the dther terlminals, can, in ,this instance, be readily assembled and electrically connected'with comparatively little expense. It will also be `noted that thepresent trouble and expense 4due to loss by breaking the porcelains is also greatly lessened by reason of the fact that the assembled plug does not have to be put into a press for 'securing the parts together. f

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. An inclosed electric fuse plug, comprising a chamberedbod a movable member mounted Within the c iamber of the body and having a projecting .indicating means, 'a spring Within the chamber to engage land operate the movable member, a fusible metal member that engages the spring, a fuse mounted Within the body and engaging the fusible metal and adapted to melt the same and release the spring With the burning of the fuse.

2. An inclosed electric fuse plug, comprising a chambered body, a removable end member mounted therein, a fuse mounted within the end member and having two external terminals, a slidable indicator piston mounted within the chamber, a spring within the chamber that engages with and for operating the indicator piston, a link of soft -metal engaging-and for normally holding the s ring and indicator, and connected with the use to be melted to release the spring by the burning of the fuse.

3. An electric fuse plug, comprising a chambered body having an outlet hole therethrough, an end insulating member tted in and against the body, a screw shall attached to the body and engaging and supporting the end member, a fuse one end of which is connected with the said shell andathe other to a contact carried by the end niember,a movable indicator member mounted within the body, a springmounted in the body adjacent to and for operatin the indicator, but engaged. and norma ly held against action by the said fuse.

4. An inclosed electric fuse plug, comprising a body having an opening therethrough, an end insulating member. itted in against the body, a screw`shell covering the body and to hold the end member in position, a terminal mounted within the end member, a fuse one end of which is connected to the said terminal and the other with the shell, a spring mounted within the end member adjacent to and ada ted to operate the movable indicating mem er, means for engaging and normally holding said spring in a contracted position, but adapted to be eected to release the spring by the burning of the fuse connecting the two said ter- 'minals.

5. An electric fuse plug, comprising a chambered body With an outlet hole therethrough, an insulating end memberfitted in and against the said chambercd body and 'having suitable slots therein, a screw shell attached to the body and covering the end insulating member to support the same, a loop spring mounted within the slots of the end member, a fuse carried by the said end member and passing through the said slot and engaging the spring in arway to normally hold the same, external terminals with which the ends of the fuse are connected, a movable indicating member mounted within the chamber and recess of the body adjacent to and adapted to be operated by the spring when released.

6. An inclosed electric fuse plug, comprising a body having an opening therethrough including an enlarged chamber, an end member titted in the chamber, a screw shell covering the body and end member,

through inclu ing an enlarg and a movable indicator within the body,

means toigoperate the indicator, a link of soft metiil engaging and for normally holding the indicator operating means, afuse connected with the link in a way to melt the fuse when heated and torelease the operating means to project the indicator from the body.

7. An/i'nclosed electric fuse plug, comprisinga bod through inclu in an enlarge chamber, an end member in t e chamber, a screw shell covering the body and end member, a terminal on the e'nd member, a fuse connectin the terminal and shell and passing through the end member, a slidable indicating pin within the chamber and opening ofthe body and adapted to be projected through` the endthereof, and means engaged by the fuse.

to project the movable member .from the.-

body by the burning of the fuse.

8. 'An inclosed electric fuse plug, comprising a bod having an o ening thereed chamber, an insulating end member within the opening, a terminal on the end member, a .terminal on the body, a fuse connecting the two terminals and passing through the end member,"

a slidable indicating pin normally within the openin ,of the body, but adaptedl to be projected t erefrom, and means engaged by the fuse to operate the movable member and extend it from the body by the burning of the fuse. v I y v 9. An indicating electric fuse plug, compin mounted 1n the chamber of the body, but

adapted to be shoved out and projected f from the body, a spring within the body to engage and operate the pin, means for normally holding the spring away from thev in, a fuse that engages the holding means,

ut adapted .to burn and to releasethe' spring. 0'

10. An electric fuse plug, com rlsing a i day of March A. H1912.

JOHN H. MILLER.

Witnesses:

C. M. NEWMAN, RUTH M. WORDEN.

.p rising a bod having a chamber therein, a 

